21212220220223 has 4 divisors (see below), whose sum is σ = 21212291280000. Its totient is φ = 21212149160448.

The previous prime is 21212220220189. The next prime is 21212220220259. The reversal of 21212220220223 is 32202202221212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21212220220223 - 2¹⁸ = 21212219958079 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212220220523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 35080223 + ... + 35679776.

It is an arithmetic number, because the mean of its divisors is an integer number (5303072820000).

Almost surely, 2^{21212220220223} is an apocalyptic number.

21212220220223 is a deficient number, since it is larger than the sum of its proper divisors (71059777).

21212220220223 is an equidigital number, since it uses as much as digits as its factorization.

21212220220223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71059776.

The product of its (nonzero) digits is 1536, while the sum is 23.

Adding to 21212220220223 its reverse (32202202221212), we get a palindrome (53414422441435).

The spelling of 21212220220223 in words is "twenty-one trillion, two hundred twelve billion, two hundred twenty million, two hundred twenty thousand, two hundred twenty-three".